The present invention relates to an apparatus for the slip-free conveyance of a yarn, and which includes two discs which are movable axially with respect to each other.
Yarn conveying devices are known from the prior art which include two discs which move axially with respect to one another, note for example DE-OS No. 30 28 316. However, prior devices of this type are not suitable for slip-free conveyance. Rather, these are designed according to their function so as to allow limited slippage because they are used as so-called overfeed rollers.
Belt delivery mechanisms, and feed cylinders with pressure or godet rolls and guide rolls, are presently utilized for slip-free conveyance of yarn. However, these prior devices have disadvantages. For example, although belt delivery systems are simple to operate, the bearings are highly stressed owing to the necessary belt tension and in addition, the belts are susceptible to wear and their useful life often amounts to only a few weeks or months. In the case of feed cylinders, the pressure rolls which press the yarn onto the feed cylinders are also very susceptible to wear and frequently have to be re-ground. Substantial energy losses also occur, owing to bearing friction and the flexing work of the rubber coating of the pressure rolls. Further, the feed cylinders and guide rolls are expensive to produce, and they operate reliably only when the arriving and issuing yarn is subjected to a minimum yarn tension. Otherwise slippage can easily occur.
It is accordingly an object of the present invention to provide a yarn conveying apparatus which provides for the slip-free advance of a yarn, and which overcomes the above noted limitations and disadvantages of the present systems.
It is also an object of the present invention to provide a yarn conveying apparatus which is simple in design, and which operates reliably and without substantial wear.